Results 81 to 90 of about 25,822 (190)
Scientists in power plays: How substantive were scientists' narratives during the COVID‐19 pandemic?
Abstract Scientists who provide expert advice must engage with policy processes. Little is known about whether and how scientists deal with the political dynamics of policy processes that are inherent to policymaking. We study this question by building on the policy dimension concept within the Narrative Policy Framework.
Jule Ksinsik, Caroline Schlaufer
wiley +1 more source
本文在张秉坚[1]改进Barker-Henderson微扰理论的基础上,将理论推广应用到链状分子流体混合物热力学性质的计算.推导过程中采用了Wertheim[2]等人的链成键理论和类似Hino-Prausnitz[3]的流体混合法则,导出了链状方阱势分子流体混合物热力学性质的解析表达式.能够计算热力学一致的Helmhotz自由能、压缩因子、内能和恒容热容.计算结果与文献计算机模拟值吻合良好.
LIANGShi-qiang(梁世强) +4 more
doaj +1 more source
The Feasibility Study on the Municipal Solid Waste Incineration Slag as Fine Aggregate of Concrete [PDF]
随着城镇化的快速推进和人民生产、生活的发展,大量增加的生活垃圾已成为全国一个比较严重的社会问题。发达国家的发展历程表明,通过焚烧可使垃圾减量80%~85%,减容约90%,但仍将残留总重约10%~20%的焚烧炉渣,大部分炉渣进入填埋场进行填埋处置,这将显著增加城市周边填埋库容的压力,占用大量的土地。 与此同时,大规模的城镇化和基础设施建设对于混凝土的需求量稳定增长,混凝土用砂数量巨大,加上砂浆和其他用途,估计每年全国需要30亿吨以上建设用砂。随着对砂子的不断开采,全国天然河砂资源趋于枯竭。福州、厦门 ...
张世相
core
ABSTRACT Why did Australia go from the White Australia Policy, which excluded non‐whites, to institutionalizing multiculturalism policy in the 1970s? This question defies traditional political ideologies of the major political parties, which had long supported the White Australia Policy. This article is a rare empirical demonstration of the Five‐Thread
Julius C. S. Mok
wiley +1 more source
罕遇地震下偏心支撑框架结构需合理有效地增大消能梁段的延性和耗能能力,并减小消能梁段的损伤,以使该种结构能更好地适应当前的抗震要求。基于剪切型消能梁段的力学特性和扩孔型螺栓连接的受剪滑移能力,提出一种扩孔螺栓连接型消能梁段。采用校正的有限元方法对扩孔型螺栓连接和扩孔螺栓连接型消能梁段进行详细分析,以明确相应试件的力学性能。研究结果表明,扩孔螺栓连接型消能梁段具有高延性和强耗能等特点,能有效提高偏心支撑框架结构的抗震性能和震后功能恢复能力,并为偏心支撑框架结构的抗震设计提供新的思路和方法。
胡淑军, 熊进刚, 宋固全
doaj
Preparation and Electromagnetic Wave Absorbing Property of SiC Fiber /Epoxy Resin Composites [PDF]
本论文对碳化硅(SiC)纤维进行热处理,制备了不同电阻率的SiC纤维;利用不同电阻率的SiC纤维与环氧树脂复合,制备单层、两层和三层复合材料,测试其在X波段下的电磁参数及吸波性能;利用传输线理论,计算预测了纤维电阻率、纤维体积分数、材料厚度和叠层方式对复合材料吸波性能的影响规律,并将实验结果与理论计算结果进行了对比验证。 研究发现,在1000-1500C温度区间,随着热处理温度的升高,SiC纤维的电阻率大幅度降低。当热处理温度达到1500C时,纤维电阻率约为1ohm.cm。随着纤维电阻率的降低 ...
李华展
core
ABSTRACT As the Narrative Policy Framework (NPF) begins to unpack issues of power and narratives, the main focus has been on power‐over and domination rather than more transformative notions of power‐to and empowerment. This article draws on insights from gender and policy studies and suggests that the NPF benefits from adopting a multifaceted notion ...
Hilda Broqvist
wiley +1 more source
Sol-Gel Preparation of Modified TiO2 Films and Its Superhydrophilicity Performance in Absence of UV Irradiation Investigation [PDF]
具有自清洁特性的超亲水薄膜,以其优异的超亲水性能,在环境净化、生物医学和建筑材料等众多领域有着广泛的实用潜力。然而,TiO2超亲水薄膜的实际应用却一直被限制。一方面,TiO2作为一种宽禁带半导体,只有在紫外光辐照条件下才具有优异的超亲水性,维持其超亲水性能强烈依赖于紫外光诱导,无法实现可见光响应或暗态下的超亲水性;另一方面TiO2超亲水薄膜受限于制备工艺的复杂和生产成本的高昂。因此,本文以钛酸正丁酯(Ti(OBu)4)为钛源,采用工艺操作简单、适合工业生产等优点的溶胶-凝胶法(Sol-Gel ...
孔令捷
core
The Inclusion Trade‐Off: Comparing the Design and Functionality of Collaborative Governance Forums
ABSTRACT Environmental challenges require collaboration across jurisdictions, often through forums or intermediary spaces for repeated interaction. A persistent forum design question concerns inclusion criteria, or which actors should be included.
Adam Wiechman +3 more
wiley +1 more source
盆式绝缘子综合性能的提高通常难以兼顾,文中基于分子动力学模拟,通过纳米掺杂辅助设计出符合要求的复合材料,进而提高其热学和力学性能。首先,通过分子模拟软件建立环氧树脂及掺杂了3种碳纳米管(未封端、半封端、全封端)的环氧树脂复合材料模型,将其导入到LAMMPS进行计算。其次,基于Reax FF对其做密度优化,得到符合实际的合理空间结构。然后,采用静态常应变法计算了该4种模型的力学性能,采用非平衡态分子动力学方法获取4种模型的热导率。结果表明:掺杂全封端的碳纳米管使复合材料的力学性能提升26.5 ...
韩智云 +5 more
doaj

